Wash the lamb's tripe very well by putting it under the tap until it is completely white. Then dry it and rub it with coarse salt and a little vinegar. Wash it well with water again and it will be ready. Then cut the lambs' feet in half and chop the middle of the front part, washing it carefully. Roll the tripe around the feet, forming small rolls. Put them in a cooking pot and cover them with water. When it begins to boil remove them and dry them well. Then put them back in the pot, covered with cold water. Cut the onion into two equal halves and stick several cloves into it. Add it to the cooking pot with a bay leaf and a little salt. When the rolls are tender, remove them from the heat and reserve some of the cooking liquid. To make the sauce, put a saucepan on the heat with a little oil. Chop the garlic and cut the bacon into small cubes and put everything in the dish to fry it. Add the flour and, after stirring, add the paprika. Finally, pour in the cooking stock, carefully and slowly, until you get a light sauce. Mix the tripe with the sauce and let it cook for ten minutes.